In concurrently filed U.S. patent application Ser. No. 398,845, entitled "A Dynamic Video System Including Automatic Contrast and `White-Stretch` Processing Sections", referred to above, the advantages of using a "white-stretch" processing section in a television system are disclosed. White-stretch emphasizes or boosts the amplitudes of mid-range luminance amplitudes relative to high luminance amplitudes as a function of a control signal representing an image characteristic in order to enhance the contrast of the reproduced image. The advantages of white stretch processing are briefly discussed in the present application. However, the present application primarily concerns an advantageous arrangement for providing a controllable non-linear gain characteristic which may be employed to produce white-stretch.